First of all ,sorry for my poor English.

On the internet , I often saw somebody says "You can new a clas without delete it if it inherits from QObject"

But in the book "C++ GUI Programming with Qt 4 Second Edition", I saw "When we create an object (a widget, validator, or any other kind) with a parent, the parent adds the object to the list of its children. When the parent is deleted, it walks through its list of children and deletes each child. The children themselves then delete all of their children, and so on recursively until none remain."

So I have a quesstion. Some object such as QString ,it inherits from QObject but have no interface.When I new a QString
1、I think it has no parent.Am I right?
2、Need I delete it?